Electromagnetic relay

ABSTRACT

A LOW PROFILE ELECTROMAGNETIC RELAY OF MODULAR CONSTRUCTION HAVING INTEGRATED COIL, BASE-CONTACT AND ARMATURE-CONTACT ASSEMBLIES TO FACILITATE FLEXIBILITY OF PREASSEMBLY. THE ARMATURE-CONTACT ASSEMBLY INCLUDES A UNITARY CONTACT-RETURN SPRING WHICH SUPPORTS AN ARMATURE AND MOVABLE CONTACTS ON THE BASE-CONTACT ASSEMBLY FOR MOVEMENT TOWARD THE COIL ASSEMBLY IN PARALLEL RELATION TO THE AXIS THEREOF IN RESPONSE TO ENERGIZATION OF AN ACTUATING COIL ASSOCIATED WITH THE COIL ASSEMBLY.

R. J. FLAHERTY ELECTROMAGNETIC RELAY S SheetS-Sheet 1 Filed Aug. 27 1971Feb. 20, 1973 R. J. FLAHERTY ELECTROMAGNETIC RELAY 3 Sheets-Sheet 2Filed Aug. 27. 1971 United States Patent 3,717,829 ELECTROMAGNETIC RELAYRoger .I. Flaherty, Oxford, Conn., assignor to Allied Control Company,Inc., Plantsville, Conn. Filed Aug. 27, 1971, Ser. No. 175,584 Int. Cl.H01h 13/12 US. Cl. 335-187 20 Claims ABSTRACT OF THE DISCLOSURE A lowprofile electromagnetic relay of modular construction having integratedcoil, base-contact and armature-contact assemblies to facilitateflexibility of preassembly. The armature-contact assembly includes aunitary contact-return spring which supports an armature and movablecontacts on the base-contact assembly for movement toward the coilassembly in parallel relation to the axis thereof in response toenergization of an actuating coil associated with the coil assembly.

BACKGROUND OF THE INVENTION This invention relates in general toelectromagnetic relays and deals more particularly with improvedminiaturized relays for use with printed circuit boards or the like.

The general aim of the present invention is to provide an improved relayof the aforedescribed general type which has a low profile to permitcircuit board stacking and which is assembled from modular components tofacilitate flexibility of pre-assembly, whereby a plurality of modifiedforms of a basic relay structure may be provided using commoncomponents. Wear points encountered in conventional relays usingactuators, armature hinges or bearings and separate return springs aresubstantially eliminated to produce relay life and assure a high degreeof reliability. In the present relay structure the internal resistanceof the relay contact circuit varies only at the point of contact betweenstationary and movable contacts.

SUMMARY OF THE INVENTION In accordance with the present invention animproved electromagnetic relay of modular construction is providedhaving a coil assembly including an actuating coil, a basecontactassembly and at least one armature-contact assembly. A unitarycontact-return spring comprises part of the armature-contact assembly,carries at least one movable contact and an armature, and is attached toa terminal mounted on the base assembly for flexure relative thereto.The armature-contact assembly is supported for arcuate movement inparallel relation to the coil axis in response to energization thereof.

BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is a perspective view of arelay embodying the present invention.

FIG. 2 is an exploded perspective view of the relay of FIG. 1, forclarity of illustration the stationary contacts associated with theright end of the base member not being shown.

FIG. 3 is a plan view of another relay embodying the present invention.

FIG. 4 is an end view of the relay of FIG. 3.

3,717,829 Patented Feb. 20, 1973 ice DETAILED DESCRIPTION OF THEPREFERRED EMBODIMENT Turning now to the drawings and referring first toFIGS. 1 and 2, a miniaturized electromagnetic relay embodying thepresent invention and indicated generally by the reference numeral 10 ischaracterized by its low profile, modular construction and two poledouble throw circuit capability. The relay 10 comprises a base-contactassembly indicated generally at 12, a motor or coil assembly designatedgenerally by the numeral 14 and an armature-contact assembly indicatedgenerally at 16. The armature-contact assembly includes a pair ofmovable contacts 18, 18 which cooperate with stationary contact members20, 20 and 22, 22 on the base assembly, as will be hereinafterdescribed.

The base-contact assembly 12, best shown in FIG. 2, includes a generallyrectangular base member 24 having an upwardly facing seating surface 25and molded from a suitable resilient plastic material such as nylon,preferably reinforced by glass fiber. A pair of bosses 26, 26 extendupwardly from the seating surface 25 at opposite ends of the base memberand have upwardly opening grooves formed therein which define seatingsurfaces 28, 28 to aid in positioning the stationary contact members 20,20 and 22, 22 on the base member. Another groove 30 formed in the basemember between the bosses 26, 26 opens through the seating surface 25and defines another seating surface 32 to aid in positioning thearmaturecontact assembly 16 on the base member 24. A particylindricalrecess 34 formed in the base member opens through the seating surface 25to receive an associated portion of the coil assembly 14. Slots 36, 36and 38, 38 respectively associated with the seating surfaces 28, 28 and32 extend downwardly through the base member to receive the stationarycontact members. Integral motor retaining brackets 40, 40 extendupwardly from the seating surface 25 at opposite ends of the recess 34and have opposing nose portions 42, 42 at the upper ends thereof whichproject inwardly or toward the center of the base member. A pair ofholes 44, 44 extend downwardly through the base member to receiveterminals associated with the coil assembly. The base member 24 is alsoprovided with a pair of notches 46, 46 in its opposite ends tofacilitate retention of a housing or cover (not shown).

A typical stationary contact member indicated at 20 in FIG. 2 includes acontact portion 48 and a terminal portion 50 which has a burr or spur 52formed thereon. The terminal portion 50 further defines downwardlyfacing bearing surfaces 54, 54 which engage an associated seatingsurface 28 when the contact member 20 is inserted into an associatedslot 36 and pressed into assembly with the base member 24. The spur 52incises and grips the base material to retain the contact member 20 inassembly with the base member 24. The stationary contact members 22, 22are substantially identical to the contact members 20, 20, but havecontact portions bent or slightly offset relative to the terminalportions thereof. Thus, a predetermined contact gap is provided betweeneach contact member 20 and its associated contact member 22 tofacilitate movement of an associated contact 18 positioned therebetween.The terminal portion of each stationary contact member projects for somedistance below the lower surface of the base member 24 to facilitateconnection of the relay with a printed circuit board or the like.

The armature-control assembly I16 includes an elongated armature 56formed of suitable paramagnetic material and having a central upwardlyopening notch 58 formed therein. The armature-contact assembly 16further includes a resilient member or return spring 60 which providesflexible hinge connection between the armature 56 and the base member24. The return spring 60 is substantially flat and has a longitudinallyextending portion 62 and an upwardly extending portion defined by a pairof spaced apart legs 64, 64. The armature 56 is attached to thelongitudinally extending portion 62 by a pair of fasteners or eyelets66, 66. Referring to FIG. 1 it should be noted that the return springhas a central part designated by the numeral 68 exposed within the notch58 and thereby spaced from the armature 56. Strips of suitableinsulating material 70, 70 are preferably fastened adjacent oppositesides of the longitudinally extending portion 62 to insulate the returnspring from the armature. The free ends of the longitudinal extendingportion 62 extend outwardly beyond the ends of the armature 56 and havethe movable contacts 18, 18 mounted thereon substantially as shown. Thearmature-contact assembly also includes a terminal or mounting assemblyindicated generally at 72 which comprises a pair of terminals 74, 74joined by an integral central connecting part 76. Each terminal has aspur 78 formed thereon spaced from the lower or free end thereof, adownwardly facing bearing surface 79 and a mounting lug 80 suitablysecured to an associated leg 64. Each lug is bent to a position out ofthe plane of its associated terminal 74.

The terminals 74, 7 4 are inserted into associated slots 38, 38 andpressed into the base member 24 so that the spurs 78, 78 incise and gripthe base material. The bearing surfaces 79, 79 engage the seatingsurface 32 to accurately position the armature-contact assembly 16 onthe basecontact assembly 12. The lugs 80, 80 support the return spring60 in a slightly upwardly and outwardly inclined position relative tothe base member 24. Each contact 18 is disposed between an associatedpair of stationary contact members and 22 and is biased into engagementwith an associated stationary contact member 20 by the spring 60.

Considering now the coil assembly 14, this assembly comprises a coilform or bobbin 91 accurately molded from suitable synthetic plasticmaterial such as nylon or the like. The bobbin 81 has an integraltubular central portion of generally rectangular cross sectionconnecting a pair of end flanges 82, 82. Base portions 84 and 86 extendoutwardly from each flange 82 and are spaced apart a distance equal tothe width of an associated bracket 40. The base portions 84, 84 and 86,86 define a downwardly facing bearing surface 88. Each base portion 86receives a coil terminal 90 which is pressed into assembly therewith andprojects downwardly therefrom. An actuating coil 92 is wound on thebobbin 80 and electrically connected to the upper ends of the coilterminals 90, 90 substantially as shown. The coil assembly 14 furtherincludes a core 93 made of suitable paramagnetic material. The core hasa generally rectangular cross-section and extends coaxially through thetubular portion of the bobbin 81 which is or maybe molded on the core.Pole pieces 94, 94 disposed at axially opposite ends of the core 93 aretransversely offset from the central portion thereof in one direction ortoward one side of the coil assembly and define transversely outwardly.facing pole faces 96, 96 disposed outwardly beyond the bobbin flanges82, 82.

In assembling the coil assembly 14 with the base 12 the terminals 90, 90are aligned with and inserted into the holes 44, 44. As the coilassembly 14 is moved into assembly with the base-contact assembly therounded nose portions 42, 42 engage the lower surfaces of the polepieces 94, 94 and cause the brackets 40, 40 on the resilient base member24 to spread slightly to receive the coil assembly 14 in snap engagementtherebetween. In assembly, a lower portion of the coil assembly l14 isdisposed within recess 34. The base portions 84, 84 and 86, 86 receivethe brackets 40, 40 therebetween and cooperate with the brackets torestrain the coil assembly 14 against transverse movement relative tothe base member 24. The coil assembly is further restrained againstlongitudinal movement relative to the base member by engagement of themotor brackets 40, 40 with the opposite end surfaces of the core 93. Therounded nose portions 42, 42 bear against upper surfaces of the polepieces 94, 94 to retain the coil assembly 14 in assembled relation withthe base-contact assembly 12.

In assembly the armature 56 is positioned with its longitudinal axis ingenerally parallel alignment with the axis of the coil 92 and each endportion of the armature transversely aligned with an associated one ofthe pole faces 96, 96. Each movable contact 18 is received between andin general transverse alignment with a set of stationary contacts 20 and22. The armature 56 is supported for generally arcuate movement orflexure relative to the base-contact assembly 12 and toward the coilassembly 14 in response to energization of the coil 92. When the coil 92is energized the opposite end portions of the armature 56 aresimutlaneously attracted by pole faces 96, 96 causing the armature tomove toward the coil assembly in parallel relation to the axis thereof.The movable contact members 18, 18 disengage the stationary contactnumbers 20, 20, engage the contact members 22, 22 and remain inengagement with the latter contact members while the coil remainsenergized. The aforesaid switching characteristics are furtherillustrated in FIG. 6, a schematic plan view of the relay 10.

The illustrated relay 10 comprises a basic structure which may beprovided in a plurality of forms each having different switchingcharacteristics by selective assembly of common parts or by alteningcertain of the parts either before or after assembly. The central part68 of the spring 60 and the connecting part 76 of the terminal assembly72 provide common electrical connection between the movable contacts 18,18 and the terminals 74, 74. However, this common electrical connectionmay, if desired, be interrupted by severing the central part 68 and theconnecting part 76 as indicated by broken lines S, S in FIGS. 1 and 2.This severing operation may be performed either before or after therelay has been assembled and for this reason the central part 68 and theconnecting part 76 are located in relatively exposed positions.

In FIGS. 7-20, various other forms of the basic relay 10 are illustratedschematically. Referring now particularly to FIGS. 7-11, five variationsof the basic relay 10 are illustrated which may be attained by selectivearrangement of the stationary contacts. In FIG. 7 a relay designated at10a includes only stationary contact members 22, 22 which are engaged bythe movable contacts 18, 18 when the coil 92 is energized. Thus, therelay 10a operates as a form A switch.

FIG. 8 illustrates a form B modification of the relay 10, designated at10b. The relay 10b includes only the stationary contacts 20, 20 whichare normally closed and which open upon energization of the relay coil92.

In FIG. 9, a further modified form of the relay 10 is illustrated anddesignated at 10c. In this illustrated form of the basic relay,stationary contacts 20 and 22 are provided at the left end of thebase-contact assembly and provide form C switching characteristics.Thus, the movable contact 18 engages the stationary contact member 20when the relay is de-energized and the contact member 22 when energized.Only a single stationary contact member 22 is provided at the oppositeend of the relay which imparts a form A characteristic to the pole atthis end of the relay.-

The relay form d illustrated in FIG. 10 includes a left pole of a form Atype and a right pole of form B type.

In FIG. 11 another modified form of the basic relay 10 is illustratedand designated at 10c and includes two poles and a common movablecontact. The relay 10e is provided with a pair of stationary contactmembers 20 and 22 at one end thereof and a single stationary contactmember 20 at its opposite end. The contacts 20, 20 are normally closed.Energization of the relay 10e causes the movable contacts 18, 18 todisengage the stationary contact members 20, 20 and one of the movablecontacts to engage its associated contact member 22. Thus, the relay10:: provides both form B and form C switching characteristics.

FIGS. 12-14 illustrate various relays respectively designated 10f-10hprovided with only one set of stationary contact members which mayinclude either or both of the stationary contacts 20 and 22.

FIGS. -20 show further schematic illustrations of the basic switch 10,designated 10i-10n which may be obtained by severing the central part 68and the connecting part 76 along the lines generally indicated at S, Sin FIGS. 1 and 2 and by providing various combinations of stationarycontacts for interaction with the resulting two electrically isolatedmovable contacts 18, 18.

Another electromagnetic relay embodying the present invention isillustrated in FIGS. 3-5 and indicated generally by the referencenumeral 100. The relay 100 is similar in many respects to the relay 10previously described and parts substantially identical to partspreviously described bear the same reference numerals as the previouslydescribed parts and will not be hereinafter further described. The relay100 includes a base-contact assembly 102 and a coil assembly 104 adaptedfor snap assembly with the base-contact assembly. A pair of armatureassemblies 16,16 mounted at diametrically opposite sides of the coilassembly 104 carry movable contacts 18, 18 which cooperate with aplurality of stationary contact members 20, and 22, 22 in the manneraforedescribed.

The base-contact assembly includes a base member 105 preferably moldedfrom a resilient plastic material. The base member 105 is generallysymmetrical about its longitudinal and transverse axis and includes anupwardly facing seating surface 106. A central recess 108 opens throughthe seating surface 106 to receive an associated lower portion of thecoil assembly 104. A pair of bosses 110, 110 project upwardly from theseating surface 106 at each end of the base member 105 and cooperatewith the latter seating surface to define upwardly opening notches 112,112. Each pair of bosses has a pair of opposing nose portions 114, 114which project into the notch 112 formed therebetween. Various slots areformed in the base member 105 to facilitate proper assembly of thevarious stationary contacts and the armature assemblies 16, 16 with thebase member 105 in the manner substantially aforedescribed.

The coil assembly 104 comprises a bobbin 116, an acuating coil 118 woundthereon and a core 120. The bobbin is preferably molded on the core andincludes a tubular central portion 122 connecting a pair of end flanges124, 124. A base or mounting portion 126 projects axially outwardly fromeach flange 124 and has a generally rectangular cross section adapted tobe received in an associated notch 112. The core 120 has a generallyrectangular cross section and includes a central portion 130'whichextends coaxially through the tubular portion 122. 'Pole pieces 132, 132disposed at axially opposite ends of the core are transversely offset inopposite directions from the central portion 130- thereof. Each polepiece 132 extends outwardly beyond an associated flange and defines atransversely outwardly facing pole face 134. Thus, the core 120 has fourpole faces 134,

134, substantially as shown. In assembly, each mounting portion 126 isreceived in snap engagement in an associated notch 112. The noseportions 114, 114 yield or spread as the mounting portions 126, 126 aresnapped into the notches 112, 112 to releasably retain the coil assembly104 in assembed relation with the base-contact assembly 102. The relayalso includes a resilient housing or cover 136 releasably retained insnap engagement with the notches 46, 46.

When the coil 118 is energized, both armatures simultaneously movetoward the coil in response to attraction of the pole pieces 132, 132.Thus, the basic operational characteristics of the relay 100 aresubstantially identical to those of the previously described relay 10.However, it should now be apparent that the basic relay 100 may bealtered in the manner substantially aforedescribed with reference to therelay 10 to provide a multiplicity of modified relay forms each havingdiffering switching characteristics.

I claim:

1. An electromagnetic relay comprising a base, a coil assembly includingan actuating coil and a core of magnetic material associated with saidcoil and having pole pieces exposed at axially opposite ends of saidcoil, means for retaining said coil assembly in fixed position relativeto said base, at least one armature assembly positioned near one side ofsaid coil and including an elongated armature made of magnetic material,resilient means providing flexible hinge connection between saidarmature and said base and supporting said armature with the1ongitudinal axis thereof generally parallel to the axis of said coiland each end portion thereof generally transversely aligned with anassociated one of said pole pieces for generally arcuate movementrelative to said base and in generally parallel relation to said coilaxis, and at least one movable contact carried by said resilient means,at least one stationary contact, and means mounting said one stationarycontact in fixed position relative to said base and in alignment withsaid movable contact to be engaged and disengaged thereby.

2. An electromagnetic relay as set forth in claim 1 wherein saidresilient means comprises at least one flat spring member having agenerally longitudinally extending portion and another portion providingsaid flexible hinge connection and said elongated armature is attachedto said longitudinally extending portion.

3. An electromagnetic relay as set forth in claim 2 wherein saidlongitudinally extending portion has one free end portion extendingoutwardly beyond one end of said elongated armature and said one movablecontact is carried by said one free end portion.

4. An electromagnetic relay as set forth in claim 3 including anothermovable contact, another stationary contact, and means mounting saidother stationary contact in fixed position relative to said base and inalignment with said other movable contact to be engaged and disengagedthereby, and wherein said longitudinally extending portion has anotherfree end portion extending outwardly beyond the other end of saidelongated armature and said other movable contact is carried by saidother free end portion.

5. An electromagnetic relay as set forth in claim 4 wherein saidlongitudinally extending portion electrically connects said one and saidother movable contact and wherein a part of said longitudinallyextending portion between said one and said other movable contacts isspaced from said elongated armature to permit severance thereof forinterrupting electrical connection between said one and said othermovable contacts whereby to alter the characteristics of said relay.

6. An electromagnetic relay as set forth in claim 4 wherein said springmember electrically connects said one and said other movable contactsand said other portion comprises a pair of legs, and including aterminal assembly comprising a pair of electrical terminals having anintegral connecting part, each of said terminals having a portionthereof projecting from said base, each of said legs being connected toan associated one of said terminals, said connecting part being exposedto permit severance thereof for interrupting electrical connectionbetween said pair of electrical terminals whereby to alter thecharacteristics of said relay.

7. An electromagnetic relay as set forth in claim 1 including anotherarmature assembly positioned near another side of said coil, at leastone other stationary contact, and means mounting said other stationarycontact in fixed position relative to said base and in alignment withsaid one movable contact carried by said other armature assembly to beengaged and disengaged thereby.

8. An electromagnetic relay as set forth in claim 7 wherein said otherside is diametrically opposite said one side.

9. An electromagnetic relay as set forth in claim 1 including a pair ofgenerally spaced apart stationary contacts, said one movable contactbeing disposed between said stationary contacts.

10. An electromagnetic relay as set forth in claim 1 wherein said meansfor retaining said coil is further characterized as means for releasablyretaining said coil assembly in snap-in assembly with said base.

11. An electromagnetic relay comprising a base-contact assemblyincluding a base member and at least one stationary contact mounted onsaid base member, at least one armature-contact assembly including anelongated armature, means for mounting said armature-contact as semblyon said base member, resilient means providing flexible hinge connectionbetween said armature and said mounting means, and at least one movablecontact car- 'ried by said resilient means and aligned with said onestationary contact for engagement and disengagement therewith inresponse to flexure of said resilient means relative to said basemember, a coil assembly including an actuating coil and a core havingpole pieces exposed at axially opposite ends of said coil, each of saidpole pieces being generally transversely aligned with an associated endportion of said armature for moving said armature and said movablecontact in a generally arcuate path relative to said base in response toenergization of said coil, and means for releasably retaining said coilassembly in snap-in assembly with said base-contact assembly.

12. An electromagnetic relay as set forth in claim 11 wherein said meansfor releasably retaining said coil assembly comprises portions of saidbase.

13. An electromagnetic relay as set forth in claim 11 wherein saidelongated armature is supported by said resilient means with thelongitudinal axis thereof generally parallel to the axis of said coilfor fiexure relative to said base member in generally parallel relationto the axis of said coil.

14. An electromagnetic relay as set forth in claim 11 wherein saidmounting means comprises an electrical terminal.

15. An electromagnetic relay as set forth in claim 14 wherein saidresilient means comprises a spring member, said spring membercooperating with said terminal and said one movable contact to provideelectrical connection therebetween.

16. An electromagnetic relay as set forth in claim wherein said base ismade from resilient material and said 8 means for retaining said coilassembly in snap-in assembly comprises integral portions of said base.

17. An electromagnetic relay as set forth in claim 2 wherein said otherportion providing said flexible hinge connection extends generallytransversely outwardly from said longitudinally extending portion.

18. An electromagnetic relay as set forth in claim 4 wherein saidarmature assembly includes means for electrically insulating saidarmature from said spring member, said armature has a notch formedtherein, and a part of said longitudinally extending portion betweensaid one and said other movable contact is disposed within said notch tofacilitate severance thereof.

19. An electromagnetic relay comprising a base, at least twolongitudinally spaced apart stationary contact members mounted on saidbase, each of said stationary contact members having a stationarycontact portion disposed above said base and a terminal portionextending through the lower surface of said base, a pair oflongitudinally spaced apart terminals mounted on said base, each of saidterminals having a portion thereof extending through the lower surfaceof said base, a coil assembly mounted on said base with the axis thereofdisposed in the longitudinal direction, said coil assembly including acoil and a core of magnetic material having pole pieces exposed ataxially opposite ends of said core, and an armature assembly including aflat spring member having a longitudinally extending portion andincluding a pair of longitudinally spaced apart leg portions extendingdownwardly from said longitudinally extending portion, each of said legportions attached at its lower end to an associated one of said terminals, a pair of movable contacts mounted at opposite ends of saidlongitudinally extending portions, each of said movable contacts beinggenerally transversely aligned with an associated stationary contactportion, and elongated armature mounted on said longitudinally extendingportion between said movable contacts and having each end portionthereof generally transversely aligned with an associated one of saidpole pieces.

20. An electromagnetic relay as set forth in claim 19 wherein saidterminals have an exposed integral connecting portion providingelectrical connection therebetween, said armature assembly includesmeans for electrically insulating said armature from said spring member,said armature has a notch formed therein and a part of saidlongitudinally extending portion between said leg portions is exposed insaid notch.

References Cited UNITED STATES PATENTS 3,184,564 3/1965 Ryckman 335-1873,618,136 11/1971 Fujita 335--202 3,518,589 6/1970 Koehler 3351323,559,132 1/1971 Bernier 335-275 3,418,608 12/1968 Angel et al. 335-1873,355,629 11/1967 Schapira 335-128 3,253,095 5/ 1966 Richert 335179HAROLD BROOME, Primary Examiner US. Cl. X.R. 335-202

